Treatment of the α-dimethylamino[3]ferrocenophane system 3 with methyl iodide followed by dimesitylphosphine (Mes PH) gave the α-(dimesitylphosphino)[3]ferrocenophane 5. This forms a frustrated Lewis pair [5/8] with B(C F ) (8) that rapidly reacts with dihydrogen under ambient conditions to probably give the phosphonium cation/hydrido borate anion salt [5-H /H-8 ]. This, however, is unstable under the applied reaction conditions with regard to replacement of the newly formed phosphonium leaving group at the ferrocenophane a-position for hydride from the [HB(C F ) ] counteranion to eventually yield the unfunctionalized [3]ferrocenophane product (10) and Mes PH· B(C F ) (11) - both characterized by independent syntheses. Analogously, Ugi's amine (6) was converted to (1-(dimesitylphosphino) -ethyl)ferrocene (7). The frustrated pair [7/8] consumes dihydrogen under similar conditions to yield the reduction products ethylferrocene (14) and Mes PH · B(C F ) (11). © 2008 American Chemical Society. 2 6 5 3 6 5 3 2 6 5 3 2 6 5 3 + - -